What is the thin line between a chubby or fat toddler? Is there actually a Body mass index for children under 6yo?

Another guide that is commonly used for children is the weight for height index, by the World Health Organization. According to the World Health Organization growth charts, a child who falls above the 98th percentile is considered to have a high weight for his/her height. You can find the chart in your child's health booklet. Generally, I feel that for children, as long as they keep to a healthy diet and are active most of the time, they should be fine. Occasional "indulgence" of fast food or processed food is alright (but key word being "occasional"). When monitoring a child's diet, the parent could pay attention to fat content. In particular, consumption of saturated fat from animal fats (e.g. fatty meat, chicken skin) and trans fat from commercial processed foods (e.g. baked products, frozen fried foods) should be kept low. Lastly, doing activities together as a family could definitely help inculcate a the good habit of maintaining an active lifestyle. Walking/jogging/cycling/rollerblading are all great activities that you can consider doing as a family. Children learn best from their parents. :)